The Influence of Prolonged Antibiotic Usage on Vitamin K Status

Abstract

SUMMARY AND CONCLUSION V KDB caused by vitamin K deficiency has been recognized as an important cause of morbidity and mortality. It was formerly called as “hemorrhagic disease of newborn,” but this term has been discarded as the etiological basis is solely due to vitamin K deficiency and to include those infants who develop VKDB beyond the usually defined 4-week neonatal period. VKDB is one of the most common causes of acquired hemostatic disorder in early infancy. A study performed on Egyptian children showed higher prevalence of late onset vitamin K deficiency bleeding than developing countries, and low serum level of vitamin K was accused as a main cause, and the main risk factors for low vitamin K serum level was antibiotic misuse and diarrhea. This study was designed to evaluate the effect of prolonged antibiotic therapy on vitamin K status in infants aged 2-24 weeks, to determine the impact of misuse of antibiotics in this age group and importance of vitamin K prophylaxis for patients on prolonged courses of antibiotics. 196 patients divided into 3 groups, group (A) 67 infants on antibiotic therapy for more than 10 days and group (B) 56 infants on antibiotic therapy for less than 10 days and group (C) 73 infants not on any antibiotics. In group (A) (77%) of the infants had serum levels of vitamin K lower than the predicted for age (300 pg/ml) with a mean value of 233pg/ml ± 114 SD compared to mean value of 608 pg/ml ± 196 SD for group (B), and group (C) showed mean value of 546pg\ml ± 195 SD. (52%) of infants in group (A) had prolonged PT, PTT and INR compared to 7% in group (B) and 6% in group (C). A significantly negative correlation between antibiotic duration and vitamin K serum level is present. The longer the antibiotic course the more affected the vitamin K status of the infant. The different classes of antibiotics evaluated in our study (cephalosporins, pencillins and metronidazole) seem to have a similar effect on the vitamin K status, but combining cephalosporins and pencillins in particular showed to have a more severe effect on the vitamin K serum level. The infants were clustered into groups based on their diagnoses (Upper respiratory tract infection, Pneumonia and Gastroenteritis) and based on the frequency of vitamin K deficient infants in the 3 groups, those with gastroenteritis were more affected and a significant correlation is present between vitamin K serum level and duration of diarrhea, the longer the duration the more affected the vitamin K levels.